SLK 230 bad misfire

[rooby_roo]

hi all, i have a v reg 230 slk with a bad misfire, it wont even idle sometimes, i have swapped the coils and leads over etc and it always comes back with misfire on cyl 1 and 3, these are the two that are just with leads on , so are these the problem, i cant try a coil pack on either cylinder as the cover holes are preventing me doing that. ?

 

[streethawk]

hi all, i have a v reg 230 slk with a bad misfire, it wont even idle sometimes, i have swapped the coils and leads over etc and it always comes back with misfire on cyl 1 and 3, these are the two that are just with leads on , so are these the problem, i cant try a coil pack on either cylinder as the cover holes are preventing me doing that. ?

Really needs plugging into a star else you'll be throwing money at it. My guess is the maf.

 

[rooby_roo]

where is the maf ? i thought it was by the air box but all i can see is the throttle body ?

 

[streethawk]

where is the maf ? i thought it was by the air box but all i can see is the throttle body ?

Standing at the front facing the car it's on your right where the pipe comes from the intercooler! Roughly around passenger headlight area

 

[rooby_roo]

update on this, both coil packs needed replacing, the car now goes like a train, but theres still a misfire when i first start the car , ?

 

[John Jones Jr]

update on this, both coil packs needed replacing, the car now goes like a train, but theres still a misfire when i first start the car , ?

I'm surprised it needed both coils simultaneously, of course it's possible but I would have said doubtful. For the current initial misfire I'd get it hooked up to STAR, as something is not right.

 

[mbenz1]

If you do need to replace the MAF, buy either a genuine MB part or Bosch. The cheaper sensors will not help very much. MAF issues are common in the M111k engine and even others like the M112.